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. 2011 Oct 18;343:d5928.
doi: 10.1136/bmj.d5928.

The Cochrane Collaboration's Tool for Assessing Risk of Bias in Randomised Trials

Free PMC article

The Cochrane Collaboration's Tool for Assessing Risk of Bias in Randomised Trials

Julian P T Higgins et al. BMJ. .
Free PMC article


Flaws in the design, conduct, analysis, and reporting of randomised trials can cause the effect of an intervention to be underestimated or overestimated. The Cochrane Collaboration’s tool for assessing risk of bias aims to make the process clearer and more accurate

Conflict of interest statement

Competing interests: All authors have completed the ICJME unified disclosure form at (available on request from the corresponding author) and declare support from the Cochrane Collaboration for the development and evaluation of the tool described; they have no financial relationships with any organisations that might have an interest in the submitted work in the previous three years and no other relationships or activities that could appear to have influenced the submitted work.


Fig 1 Example presentation of risk of bias assessments for studies in a Cochrane review of therapeutic monitoring of antiretroviral drugs in people with HIV

Comment in

  • RoB 2: a revised tool for assessing risk of bias in randomised trials.
    Sterne JAC, Savović J, Page MJ, Elbers RG, Blencowe NS, Boutron I, Cates CJ, Cheng HY, Corbett MS, Eldridge SM, Emberson JR, Hernán MA, Hopewell S, Hróbjartsson A, Junqueira DR, Jüni P, Kirkham JJ, Lasserson T, Li T, McAleenan A, Reeves BC, Shepperd S, Shrier I, Stewart LA, Tilling K, White IR, Whiting PF, Higgins JPT. Sterne JAC, et al. BMJ. 2019 Aug 28;366:l4898. doi: 10.1136/bmj.l4898. BMJ. 2019. PMID: 31462531 No abstract available.

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